EP 1297361 B1 20060614 - METHOD FOR DOWNHOLE WAVEFORM TRACKING AND SONIC LABELING
Title (en)
METHOD FOR DOWNHOLE WAVEFORM TRACKING AND SONIC LABELING
Title (de)
BOHRLOCHWELLENFORMNACHLAUF- UND SCHALLKARAKTERISIERUNGS-VERFAHREN
Title (fr)
PROCEDES D'ANALYSE SEQUENTIELLE DE SIGNAUX ET DE CLASSIFICATION SONIQUE DE ZONES DE FOND DE TROU
Publication
Application
Priority
- US 0117469 W 20010529
- US 59140500 A 20000612
Abstract (en)
[origin: WO0196904A2] Methods for downhole waveform tracking and sonic labeling employ "tracking algorithms" and Bayesian analysis to classify STC waveforms. More particularly, according to the tracking part of the invention, a probability model is built to distinguish true "arrivals" (e.g. compressional, shear, etc.) from "false alarms (e.g. noise) before the arrivals are classified. The probability model maps the "continuity" of tracks (slowness/time over depth) and is used to determine whether sequences of measurements are sufficiently "continuous" to be classified as tracks. The probability model is used to evaluate the likelihood of the data in various possible classifications (hypotheses). Prior and posterior probabalities are constructed for each track using the tracking algorithm. The posterior probabilities are computed sequentially and recursively, updating the probabilities after each measurement frame at depth <i>k</i> is acquired. The classification part of the invention determines the hypotheses with the maximum "posterior probability" according to Bayes' Theorem.
IPC 8 full level
CPC (source: EP US)
G01V 1/288 (2013.01 - EP US); G01V 1/48 (2013.01 - EP US)
Designated contracting state (EPC)
DK FR GB IT NL
DOCDB simple family (publication)
WO 0196904 A2 20011220; WO 0196904 A3 20020328; AU 1474902 A 20011224; EP 1297361 A2 20030402; EP 1297361 B1 20060614; US 6625541 B1 20030923
DOCDB simple family (application)
US 0117469 W 20010529; AU 1474902 A 20010529; EP 01984019 A 20010529; US 59140500 A 20000612